You built a form in Word, exported it to PDF, and sent it out. Half the recipients printed it, filled it by hand, photographed it, and emailed back a crooked JPEG. The other half asked you to send a Word version.
That happens because exporting to PDF does not create form fields. The lines and boxes you drew are just ink on the page. Making a PDF genuinely fillable means adding interactive field objects to it, and there are two routes: build them properly, or design the flat form so well that people can complete it with a free annotation tool.
Both are legitimate. Which you want depends on whether you need the data back in structured form.
What a fillable PDF actually contains
A fillable PDF carries an AcroForm — a collection of field objects, each with a name, a type, a position, and rules. Text fields, checkboxes, radio buttons, dropdowns, list boxes, and signature fields. The reader knows they exist, so clicking gives you a cursor, Tab moves between them in a defined order, and the values are stored as structured data rather than drawn text.
That last point is the real reason to build proper fields. If you need to collect two hundred completed forms and get the answers into a spreadsheet, field values can be exported. Text drawn on a page cannot.
There is also a second, older technology called XFA — Adobe's XML-based form architecture, used by some government and financial institutions. Most tools and all browsers cannot render XFA forms, which is why some official forms display a message insisting you open them in Adobe Acrobat Reader. That message is accurate. Do not build new forms this way. See XFA forms explained.
Route 1: build real form fields
Adobe Acrobat Pro is the standard. Prepare Form auto-detects likely fields from your layout — it finds the underlines and boxes and proposes fields for them — then you correct its guesses. It handles field naming, tab order, validation, calculated fields, and required-field enforcement. Subscription-based, and genuinely good at this.
LibreOffice Writer does it free. The Form Controls toolbar inserts text boxes, checkboxes, and dropdowns, and exporting to PDF with "Create PDF form" enabled produces a working AcroForm. Less polished than Acrobat and entirely capable for straightforward forms. This is the best free option and most people do not know it exists.
PDF-XChange Editor includes form creation on Windows, much of it in the free version.
Scripting. pdf-lib (JavaScript) and pypdf/pdfrw (Python) can add fields programmatically — the right approach for generating many forms from a template.
Online form builders — Jotform, Google Forms, Typeform — are worth considering instead. If what you actually want is to collect responses, a web form beats a PDF: no software required, validation is built in, and answers arrive in a spreadsheet automatically. People reach for PDF forms out of habit when a web form would serve everyone better. Use a PDF when the document itself matters — because it must be signed, printed, filed, or archived as a record.
Route 2: design a flat form people can complete anyway
If you do not need structured data back, a well-designed flat PDF plus a free annotation tool works fine, and it is what a great many organisations actually do.
The design does all the work here:
- Use generous underlines for text entry, not tight boxes.
___________________with room above it for text to sit. - Use open squares ☐ for checkboxes, large enough to place a mark inside without ambiguity. Small adjacent boxes are the single most common source of unclear answers.
- Leave real space. A signature line needs 15–20mm of height. Cramped fields produce cramped, illegible answers.
- Label everything explicitly — "Full name (as on passport)", not "Name".
- Put one question per line where you can. Multiple fields sharing a line get misaligned answers.
- Say what format you want. "Date (DD/MM/YYYY)" prevents the most common data problem in existence.
- Include a line telling people how to fill it in digitally. Something like: "This form can be completed on screen — no printing needed." Most people do not know that is possible, which is why they print.
Recipients can then complete it with any annotation tool, including Docento.app, which adds text, checkmark stamps, and signatures in the browser without uploading the file. See how to fill out a PDF form.
To be clear about our scope: we fill forms, we do not build them. For creating interactive fields, use LibreOffice or Acrobat from the list above.
Getting a real form right
If you do build proper fields, the details that separate a good form from an infuriating one:
Name fields meaningfully. applicant_surname, not Text14. You will thank yourself when exporting the data, and screen readers read field names aloud.
Set the tab order deliberately. Auto-detected order follows the order fields were created, which is frequently not reading order. Nothing signals a sloppy form faster than Tab jumping from the first line to the bottom of the page.
Add tooltips. They appear on hover and are read by screen readers, making them the accessible way to explain a field's requirements.
Size fields for real answers. Long addresses and hyphenated surnames overflow, and overflowing text can be silently truncated on print — a genuinely damaging failure on an application form.
Use validation sparingly. Format checks on dates and numbers help. Over-strict validation that rejects legitimate international phone numbers and addresses just blocks people.
Test on a phone and in a browser, not only in Acrobat. Many recipients will open it in Chrome or on an iPhone.
Decide about flattening. Tell recipients whether to return the form flat. A flat return cannot be altered afterwards; an unflattened one preserves the structured data you may want to extract. See how to flatten a PDF.
Do not password-protect a form you want completed. It is a reliable way to guarantee it comes back on paper.
